1. Field
Embodiments of the present invention relate to a foldable display device, and more particularly, to a foldable display device enhanced in flexibility thereof.
2. Description of the Related Art
In recent times, the field of foldable display devices is undergoing significant development. Such flexible display devices exhibit versatility thereof in various fields of application due to the capability of being used when folded or curved. A flexible display device is provided by a display element being disposed on a flexible substrate.
Examples of such a display element applicable to a flexible display device include an organic light emitting diode (OLED) element, a liquid crystal display (LCD) element, an electrophoretic display (EPD) element, and the like. Among these, an OLED element is considered to be appropriate for a display element of a flexible display device due to having excellent flexibility given that an OLED element is manufactured in a stacked structure having a thin film shape.
Flexible display devices are classified into types thereof including a rollable display device capable of being rolled into a scroll shape based on bendability thereof, a foldable display device capable of being folded like a paper, and a stretchable display device capable of being elongated and compressed, and the like.
In particular, a foldable display device is garnering attention as a next generation display device due to the ease of portability when a screen thereof is folded and the ability to achieve a relatively large display area on the screen when unfolded.
Meanwhile, a foldable display device may include a display panel and a cover window disposed on the display panel. The cover window may include a hard coating layer having a hardness exceeding a predetermined level thereof. Although such a hard coating layer is advantageous for protecting the display panel, issues may arise when a hard coating layer is used in a display device having a bendable property such as a foldable display device due to the potential brittleness of a hard coating layer under a bending force.
It is to be understood that this background of the technology section is intended to provide useful background for understanding the technology and as such disclosed herein, the technology background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of subject matter disclosed herein.